Two minor issues in env variable exporting for SDL2 GameController support

[anonymous255]

Hello,

Sorry, really should make a pull request, but I'm a bit short on time and it's just a one-liner so I'll post my suggested changes below:

export SDL_GAMECONTROLLERCONFIG="0000000057696920552047616d654300,Wii U > GameCube Adapter Port 1,platform:Linux,x:b3,a:b0,b:b1,y:b2,start:b7,dpleft:b10,dpdown:b9,dpright:b11,dpup:b8,leftshoulder:b4,lefttrigger:a2,rightshoulder:b5,righttrigger:a5,leftx:a0,lefty:a1,rightx:a3,righty:a4,"

The changes are as follows:

1. rightshoulder:b6 is incorrect, should be 'b5'... (or should it? 'b6' is the Z-button, 'b5' is the digital component of the right shoulder button. Could work either way, but 'b5' makes more since given Add SDL_GameController config information #2)
2. leftshoulder is not listed, should be 'leftshoulder:b4' ('b4' corresponds with the digital component of the left shoulder button [analog component is 'a2'])

Concerning the Z-button vs. Right Shoulder conflict, it's probably fine either way, but a note in SDL_GameController.txt on how to change it would be nice.

Apologies for the lack of a nice pull request, hope this is helpful!

[ToadKing]

Shoulder and trigger buttons are different. Triggers are mapped to the large analog triggers and right shoulder is mapped to the z button.

The only issue might be the triggers which are mapped to the analog values which some games might not support.